package com.soft.mainsite.component.spring;

import org.apache.commons.lang3.Validate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Lazy;
import org.springframework.stereotype.Service;


/**
 * Description:SpringContextHolder
 *
 * @author Jin
 * @create 2017-05-18
 **/
@Service
@Lazy(false)
public class SpringContextHolder implements ApplicationContextAware {

    private static ApplicationContext applicationContext = null;

    private static Logger log = LoggerFactory.getLogger(SpringContextHolder.class);

    /**
     * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型
     *
     * @param name
     * @param <T>
     * @return
     */
    public static <T> T getBean(String name) {
        assertContextInjected();
        return (T) applicationContext.getBean(name);
    }

    /**
     * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型
     *
     * @param requiredType
     * @param <T>
     * @return
     */
    public static <T> T getBean(Class<T> requiredType) {
        assertContextInjected();
        return applicationContext.getBean(requiredType);
    }

    /**
     * 清除SpringContextHolder中的ApplicationContext为Null
     */
    public static void clearHolder() {
        if (log.isDebugEnabled()) {
            log.debug("清除SpringContextHolder中的ApplicationContext:" + applicationContext);
        }
        applicationContext = null;
    }

    /**
     * 注入Context到静态变量中
     *
     * @param applicationContext
     */
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) {
        log.debug("*************************** [SpringContextHolder Init] ******************************");
        SpringContextHolder.applicationContext = applicationContext;
    }

    /**
     * 检查ApplicationContext不为空
     */
    private static void assertContextInjected() {
        Validate.validState(applicationContext != null, "applicaitonContext属性未注入！");
    }
}
